Enzymatic synthesis of glucosyl rebaudioside A and its characterization as a sweetner - FFM&F Lab, SNU (기능성 식품소재 및 발효 연구실)

Rebaudioside A was modified via glucosylation by recombinant dextransucrase of Leuconostoc lactis EG001 in Escherichia coli BL21 (DE3), forming single O-α-D-glucosyl-(1″→6′) rebaudioside A with yield of 86%. O-α-D-glucosyl-(1″→6′) rebaudioside A was purified using HPLC and Diaion HP-20 and its properties were characterized for possible use as a food ingredient. Almost 98% of O-α-D-glucosyl-(1″→6′) rebaudioside A was dissolved after 15 days of storage at room temperature, compared to only 11% for rebaudioside A. Compared to rebaudioside A, O-α-D-glucosyl-(1″→6′) rebaudioside A showed similar or improved acidic or thermal stability in commercial drinks. Thus, O-α-D-glucosyl-(1″→6′) rebaudioside A could be used as a highly pure and improved sweetener with high stability in commercial drinks.

Practical Application

The proposed method can be used to generate glucosyl rebaudioside A by enzymatic glucosylation. Simple glucosyl rebaudioside A exhibited high acid/thermal stability and improved sweetener in commercialized drinks. This method can be applied to obtain high value-added bioactive compounds by enzymatic modification.